JP2747216B2 - Thin film magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head used for a magnetic disk drive.

[0002]

2. Description of the Related Art A thin-film magnetic head used in a magnetic disk drive is provided with a coil having a lower magnetic film and an interlayer insulating layer on one surface of a substrate, and an upper magnetic film and a protective film sequentially formed by applying semiconductor manufacturing technology. (See JP-A-55-84020). The conventional thin-film magnetic head having such a configuration can have a very small physical size, so that the inductance can be reduced, and therefore the high-frequency characteristics are good and the high-speed data transfer is possible. It is widely used as a magnetic recording element advantageous for high-density recording.

However, as a problem specific to the thin-film magnetic head, it is known that an abnormal waveform called a wiggle occurs in the waveform of the read signal. As one means for solving this problem, a method has been proposed in which the component gradient of the composition in the upper magnetic film is made zero (see JP-A-57-10191).

As another means, there has been proposed a means for suppressing the wiggle by setting the rising portions of the yoke region and the pole region of the upper magnetic film at a distance of 2 μm to 12 μm from the air bearing surface ( See JP-A-3-97110).

[0005]

The above-mentioned conventional wiggle suppressing means for a thin-film magnetic head as described above is experimentally possible in the former case where the component gradient of the composition in the upper magnetic film is made zero. However, when applied to mass production, it is extremely difficult to control the plating process, which is the process of forming the upper magnetic film, and there is a problem that the manufacturing cost increases.

On the other hand, the rising portions of the yoke region and the pole region of the upper magnetic film are set to 2 μm to 12 μm from the air bearing surface.
In the latter case where the distance is set at a distance of μm, this is a simple means and an attractive means in terms of manufacturing cost. However, since the allowable range of the wiggle is 2.4%, the current technology has been significantly advanced. It does not fit the actual situation.

[0007]

Means for Solving the Problems A thin film magnetic head of the present invention, thin-film magnetic head obtained by sequentially stacking a coil and the upper magnetic film having a lower magnetic film and formic cap film and an interlayer insulating layer on one surface of the substrate , A third magnetic layer is provided on the upper magnetic film, and a distance D from an air bearing surface on a side surface of the substrate to an end of the third magnetic layer is 1
0 μm < D ≦ 18 μm or 12 μm ≦ D ≦ 16 μ
m.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a plan view of the embodiment of FIG. 1, and FIG.
FIG. 4 is a characteristic diagram showing the relationship between the distance D and the occurrence rate of the wiggle in the embodiment of FIG.

[0010] 1 to 3, the substrate 1, AlTiC _{(Al 2 O 3 -T i C} ) ceramic is formed in such insulating film 2 is formed thereon. Insulating film 2
Is formed by sputtering using alumina (Al ₂ O ₃ ).

[0011] on the insulating film 2, Permalloy (N _i F
e), a lower magnetic film 3 formed by a plating method is formed, and alumina (Al ₂ O) is further formed thereon.
₃ ) Gap film 4 formed by sputtering method
Are formed.

On the gap film 4, a coil 5 formed by plating using copper (Cu) is formed, and an interlayer insulating film (coil insulating film ) for insulating between layers of the coil 5 is formed.
The film 6 is formed by subjecting a photoresist to a thermosetting treatment.

[0013] upper magnetic layer 7 on the interlayer insulating film 6, similar to the lower magnetic film 3, using a permalloy (N _i Fe) is formed by a plating method, further thereon, a third magnetic A magnetic film 8 as a layer is formed.

The material of the magnetic film 8 is a saturation magnetic flux density (Bs).
Although may be any material having high, in the present embodiment, the ease of manufacturing, the same permalloy (N _i and the upper magnetic film 7
Fe) is used.

Further, terminals (not shown) for transmitting and receiving signals to and from the coil 5 and leads 10 are formed, and the whole of these is covered with a protective film 9 to form a thin-film magnetic head.

The lower magnetic film 3 and the upper magnetic film 7 are directly coupled behind the coil 5 (see FIG. 3).
The gap film 4 is interposed between them on the air bearing surface 11 side of the end surface.

A spirally formed coil 5 passes between the lower magnetic film 3 and the upper magnetic film 7 to constitute a magnetic circuit.

A magnetic film 8 is formed on the upper magnetic film 7 to increase the apparent thickness of the upper magnetic film 7, but its tip is located at a distance D from the air bearing surface 11. Position.

The purpose of forming the magnetic film 8 is to form the upper magnetic film 7
Is to avoid magnetic saturation of magnetic flux generated when a current flows through the coil 5 and improve electromagnetic conversion efficiency.

As described above, the magnetic film 8 is formed on the upper magnetic film 7.
And a distance D from the air bearing surface 11 at the tip thereof.
When 12 μm ≦ D ≦ 16 μm, it is possible to suppress the occurrence of wiggle.

That is, the distance D is set to 10 μm, 13 μm, 16 μm, and 19 μm, and the write / read operation is performed 50 times to calculate the average value of the read voltage as X, the standard deviation as δ, and (δ / X) × 100%. As shown by the curve 21 in FIG.
It has a local minimum near μm. Therefore, when setting 12 μm ≦ D ≦ 16 μm in consideration of the production yield, the wiggle generation rate can be reduced to 1.05% or less. When the wiggle generation ratio may be about 1.10% or less, it is possible to set 10 μm ≦ D ≦ 18 μm.

[0022]

As described above, in the thin-film magnetic head of the present invention, the third magnetic layer is formed on the upper magnetic film, and the distance D from the air bearing surface of the end surface of the substrate at the tip is determined. (For example, 12 μm ≦ D ≦ 16 μ)
By setting m), there is an effect that the generation rate of the wiggle can be suppressed to a desired value or less.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment of FIG.

FIG. 3 is a sectional view taken along line AA of the embodiment of FIG. 1;

FIG. 4 is a characteristic diagram showing a relationship between a distance D and a wiggle occurrence rate in the embodiment of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Insulating film 3 Lower magnetic film 4 Gap film 5 Coil 6 Interlayer insulating film 7 Upper magnetic film 8 Magnetic film 9 Protective film 10 Lead 11 Air bearing surface 21 Curve

Claims (2)

(57) [Claims] 1. A thin-film magnetic head obtained by sequentially stacking a coil and the upper magnetic film having a substrate lower magnetic film and formic <br/> cap film and an interlayer insulating layer on one face of, on the upper magnetic film the third magnetic layer is provided, a thin film magnetic head is characterized in that the distance D from the air bearing surface side of said substrate to an end portion of the third magnetic layer was changed to 10 [mu] m <D ≦ 18 [mu] m to. 2. A method according to claim 1 , wherein the lower magnetic film and the giant magnetic layer
Coil having cap film and interlayer insulating layer and upper magnet
In a thin film magnetic head in which conductive films are sequentially laminated,
A third magnetic layer is provided on the partial magnetic film, and a third magnetic layer is provided on a side surface of the substrate.
Wherein the air bearing surface and the third thin film magnetic head you <br/> characterized in that the distance <br/> away D to the end of the magnetic layer was changed to 12 [mu] m ≦ D ≦ 16 [mu] m.